Nevermind, just googled it up. I was thinking of a different program.
Looks like it was a C program. I would think modifying it for Carbon would not be a big deal. Heck might be kinda fun for someone like me (archaeologist turned programmer).
:)
Thanks, good idea; here's the links to the abstract and the archive, which includes the author's contact information as of Dec 2000. The read me file in the archive has some amusing things in regarding the Mayan calendar.
http://hyperarchive.lcs.mit.edu/HyperArchive/Abstracts/app/time/chac-111.hqx.txt
http://hyperarchive.lcs.mit.edu/HyperArchive/Archive/app/time/chac-111.hqx